title: CaMKII inhibition rectifies arrhythmic phenotype in a patient-specific model of catecholaminergic polymorphic ventricular tachycardia.
abstract: Induced pluripotent stem cells (iPSC) offer a unique opportunity for developmental studies, disease modeling and regenerative medicine approaches in humans. The aim of our study was to create an in vitro 'patient-specific cell-based system' that could facilitate the screening of new therapeutic molecules for the treatment of catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited form of fatal arrhythmia. Here, we report the development of a cardiac model of CPVT through the generation of iPSC from a CPVT patient carrying a heterozygous mutation in the cardiac ryanodine receptor gene (RyR2) and their subsequent differentiation into cardiomyocytes (CMs). Whole-cell patch-clamp and intracellular electrical recordings of spontaneously beating cells revealed the presence of delayed afterdepolarizations (DADs) in CPVT-CMs, both in resting conditions and after β-adrenergic stimulation, resembling the cardiac phenotype of the patients. Furthermore, treatment with KN-93 (2-[N-(2-hydroxyethyl)]-N-(4methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine), an antiarrhythmic drug that inhibits Ca(2+)/calmodulin-dependent serine-threonine protein kinase II (CaMKII), drastically reduced the presence of DADs in CVPT-CMs, rescuing the arrhythmic phenotype induced by catecholaminergic stress. In addition, intracellular calcium transient measurements on 3D beating clusters by fast resolution optical mapping showed that CPVT clusters developed multiple calcium transients, whereas in the wild-type clusters, only single initiations were detected. Such instability is aggravated in the presence of isoproterenol and is attenuated by KN-93. As seen in our RyR2 knock-in CPVT mice, the antiarrhythmic effect of KN-93 is confirmed in these human iPSC-derived cardiac cells, supporting the role of this in vitro system for drug screening and optimization of clinical treatment strategies.
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, National Research Council of Italy, Milan, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Di Pasquale
authors.forename: F
authors.initials: F
authors.lastname: Lodola
authors.forename: M
authors.identifier: 0000000240584368
authors.initials: M
authors.lastname: Miragoli
authors.forename: M
authors.initials: M
authors.lastname: Denegri
authors.forename: J E
authors.initials: JE
authors.lastname: Avelino-Cruz
authors.forename: M
authors.initials: M
authors.lastname: Buonocore
authors.forename: H
authors.initials: H
authors.lastname: Nakahama
authors.forename: P
authors.initials: P
authors.lastname: Portararo
authors.forename: R
authors.initials: R
authors.lastname: Bloise
authors.forename: C
authors.initials: C
authors.lastname: Napolitano
authors.forename: G
authors.initials: G
authors.lastname: Condorelli
authors.forename: S G
authors.initials: SG
authors.lastname: Priori
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D001483:Base Sequence; D001596:Benzylamines / Q000494:pharmacology* / Q000627:therapeutic use*; D002118:Calcium / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D005260:Female; D057809:HEK293 Cells; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D010375:Pedigree; D010641:Phenotype; D047428:Protein Kinase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics; D013449:Sulfonamides / Q000494:pharmacology* / Q000627:therapeutic use*; D017180:Tachycardia, Ventricular / Q000150:complications / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D000098850:Polymorphic Catecholaminergic Ventricular Tachycardia; D000096926:Benzenesulfonamides
chemical_list: D001596:Benzylamines; D002118:Calcium; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D047428:Protein Kinase Inhibitors; D011943:Receptors, Adrenergic, beta; D019837:Ryanodine Receptor Calcium Release Channel; D013449:Sulfonamides; C072105:KN 93; D000096926:Benzenesulfonamides